Chord Progression Builder with Audio Preview

A free chord progression builder. Pick a key, mood and genre to see Roman numerals turn into real chord names, then press play to hear each progression in the browser.

The play button uses your browser’s built-in audio. It starts on your click, so no sound plays until you press it.
Chord Progressions

Roman numerals you can hear

Pick a key, mood and genre to see numerals become real chord names, then press play to hear the progression right in your browser. No sample packs, no external synth.

What Is a Chord Progression Builder?

A chord progression builder takes abstract theory and shows it in two languages at once. On one side you get the Roman numerals (I, V, vi, IV), which travel between every key; on the other side you get the actual chord names for the key you picked. The numerals let you borrow ideas across songs, and the names tell your fingers exactly what to play. When you press the play button, a small Web Audio schedule turns each chord into three quiet oscillators, so you can hear whether the mood you picked actually matches the feeling in your head.

How It Works

1
Choose key and qualityPick a root note and a major or minor quality. Minor keys use the natural minor scale and minor numerals.
2
Pick mood and genreFour typical progressions for the mood load, transposed into your key. Genre changes the voicing: jazz adds sevenths, rock strips to root and fifth, R&B tints with a ninth.
3
Read both sidesNumerals sit on top, portable across keys; chord names below are the shape applied to your chosen key.
4
Press playThe browser plays the four chords in sequence. Because browsers only allow audio after a gesture, sound starts the moment you click.

Tips for Best Results

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Start from the moodOnce the feeling is right, transpose the numerals up or down until the melody sits comfortably in your voice.
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Try V for viIf a progression feels too final, swap the last V for a vi and it wants another verse.
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Jazz a pop loopA maj7 on the IV instantly ages the song by twenty years.
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Play it twiceThe first listen tells you if the direction is right; the second tells you if the turnaround at the end lands.

Who It’s For

Guitarists and keyboardistsHunting a fresh four-chord loop.
Producers and studentsSketching harmony before the beat, or learning how Roman numerals map to real keys. The site is maintained by Mel; more companions live on the tools hub.
LyricistsWriting words first and adding chords later. Pair a progression with the song structure builder so chorus and bridge sit on different harmonic ground, and color the lyrics with the mood word bank.

Frequently Asked Questions

Why do I see Roman numerals instead of just chords?
Numerals describe the shape of the progression, which stays the same when you change key. Chord names are the shape applied to your chosen key.
Does the audio require an internet connection?
No. The sound is synthesized by your browser the moment you press play; nothing is streamed.
Are minor keys supported?
Yes. Pick Minor as the key quality and the tool uses the natural minor scale and minor numerals (i, iv, VI, VII).
Can I use these progressions in released songs?
Yes. Common harmonic patterns are not copyrightable; the melody, lyrics and arrangement you build on them are yours.